You really do not have to worry about whether he opts out. If you are the custodial parent for 2021 and you claim the children on your own 2021 tax return, then paying back the advance payments will be "his" problem--not yours. As already stated, you can get the CTC on your own 2021 return.
**Disclaimer: Every effort has been made to offer the most correct information possible. The poster disclaims any legal responsibility for the accuracy of the information that is contained in this post.**
